1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2007 Oracle. All rights reserved. 4 */ 5 6 #include "ctree.h" 7 #include "fs.h" 8 #include "messages.h" 9 #include "inode-item.h" 10 #include "disk-io.h" 11 #include "transaction.h" 12 #include "print-tree.h" 13 #include "space-info.h" 14 #include "accessors.h" 15 16 struct btrfs_inode_ref *btrfs_find_name_in_backref(struct extent_buffer *leaf, 17 int slot, 18 const struct fscrypt_str *name) 19 { 20 struct btrfs_inode_ref *ref; 21 unsigned long ptr; 22 unsigned long name_ptr; 23 u32 item_size; 24 u32 cur_offset = 0; 25 int len; 26 27 item_size = btrfs_item_size(leaf, slot); 28 ptr = btrfs_item_ptr_offset(leaf, slot); 29 while (cur_offset < item_size) { 30 ref = (struct btrfs_inode_ref *)(ptr + cur_offset); 31 len = btrfs_inode_ref_name_len(leaf, ref); 32 name_ptr = (unsigned long)(ref + 1); 33 cur_offset += len + sizeof(*ref); 34 if (len != name->len) 35 continue; 36 if (memcmp_extent_buffer(leaf, name->name, name_ptr, 37 name->len) == 0) 38 return ref; 39 } 40 return NULL; 41 } 42 43 struct btrfs_inode_extref *btrfs_find_name_in_ext_backref( 44 struct extent_buffer *leaf, int slot, u64 ref_objectid, 45 const struct fscrypt_str *name) 46 { 47 struct btrfs_inode_extref *extref; 48 unsigned long ptr; 49 unsigned long name_ptr; 50 u32 item_size; 51 u32 cur_offset = 0; 52 int ref_name_len; 53 54 item_size = btrfs_item_size(leaf, slot); 55 ptr = btrfs_item_ptr_offset(leaf, slot); 56 57 /* 58 * Search all extended backrefs in this item. We're only 59 * looking through any collisions so most of the time this is 60 * just going to compare against one buffer. If all is well, 61 * we'll return success and the inode ref object. 62 */ 63 while (cur_offset < item_size) { 64 extref = (struct btrfs_inode_extref *) (ptr + cur_offset); 65 name_ptr = (unsigned long)(&extref->name); 66 ref_name_len = btrfs_inode_extref_name_len(leaf, extref); 67 68 if (ref_name_len == name->len && 69 btrfs_inode_extref_parent(leaf, extref) == ref_objectid && 70 (memcmp_extent_buffer(leaf, name->name, name_ptr, 71 name->len) == 0)) 72 return extref; 73 74 cur_offset += ref_name_len + sizeof(*extref); 75 } 76 return NULL; 77 } 78 79 /* Returns NULL if no extref found */ 80 struct btrfs_inode_extref * 81 btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans, 82 struct btrfs_root *root, 83 struct btrfs_path *path, 84 const struct fscrypt_str *name, 85 u64 inode_objectid, u64 ref_objectid, int ins_len, 86 int cow) 87 { 88 int ret; 89 struct btrfs_key key; 90 91 key.objectid = inode_objectid; 92 key.type = BTRFS_INODE_EXTREF_KEY; 93 key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len); 94 95 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow); 96 if (ret < 0) 97 return ERR_PTR(ret); 98 if (ret > 0) 99 return NULL; 100 return btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0], 101 ref_objectid, name); 102 103 } 104 105 static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans, 106 struct btrfs_root *root, 107 const struct fscrypt_str *name, 108 u64 inode_objectid, u64 ref_objectid, 109 u64 *index) 110 { 111 struct btrfs_path *path; 112 struct btrfs_key key; 113 struct btrfs_inode_extref *extref; 114 struct extent_buffer *leaf; 115 int ret; 116 int del_len = name->len + sizeof(*extref); 117 unsigned long ptr; 118 unsigned long item_start; 119 u32 item_size; 120 121 key.objectid = inode_objectid; 122 key.type = BTRFS_INODE_EXTREF_KEY; 123 key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len); 124 125 path = btrfs_alloc_path(); 126 if (!path) 127 return -ENOMEM; 128 129 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 130 if (ret > 0) 131 ret = -ENOENT; 132 if (ret < 0) 133 goto out; 134 135 /* 136 * Sanity check - did we find the right item for this name? 137 * This should always succeed so error here will make the FS 138 * readonly. 139 */ 140 extref = btrfs_find_name_in_ext_backref(path->nodes[0], path->slots[0], 141 ref_objectid, name); 142 if (!extref) { 143 btrfs_handle_fs_error(root->fs_info, -ENOENT, NULL); 144 ret = -EROFS; 145 goto out; 146 } 147 148 leaf = path->nodes[0]; 149 item_size = btrfs_item_size(leaf, path->slots[0]); 150 if (index) 151 *index = btrfs_inode_extref_index(leaf, extref); 152 153 if (del_len == item_size) { 154 /* 155 * Common case only one ref in the item, remove the 156 * whole item. 157 */ 158 ret = btrfs_del_item(trans, root, path); 159 goto out; 160 } 161 162 ptr = (unsigned long)extref; 163 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]); 164 165 memmove_extent_buffer(leaf, ptr, ptr + del_len, 166 item_size - (ptr + del_len - item_start)); 167 168 btrfs_truncate_item(path, item_size - del_len, 1); 169 170 out: 171 btrfs_free_path(path); 172 173 return ret; 174 } 175 176 int btrfs_del_inode_ref(struct btrfs_trans_handle *trans, 177 struct btrfs_root *root, const struct fscrypt_str *name, 178 u64 inode_objectid, u64 ref_objectid, u64 *index) 179 { 180 struct btrfs_path *path; 181 struct btrfs_key key; 182 struct btrfs_inode_ref *ref; 183 struct extent_buffer *leaf; 184 unsigned long ptr; 185 unsigned long item_start; 186 u32 item_size; 187 u32 sub_item_len; 188 int ret; 189 int search_ext_refs = 0; 190 int del_len = name->len + sizeof(*ref); 191 192 key.objectid = inode_objectid; 193 key.offset = ref_objectid; 194 key.type = BTRFS_INODE_REF_KEY; 195 196 path = btrfs_alloc_path(); 197 if (!path) 198 return -ENOMEM; 199 200 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 201 if (ret > 0) { 202 ret = -ENOENT; 203 search_ext_refs = 1; 204 goto out; 205 } else if (ret < 0) { 206 goto out; 207 } 208 209 ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], name); 210 if (!ref) { 211 ret = -ENOENT; 212 search_ext_refs = 1; 213 goto out; 214 } 215 leaf = path->nodes[0]; 216 item_size = btrfs_item_size(leaf, path->slots[0]); 217 218 if (index) 219 *index = btrfs_inode_ref_index(leaf, ref); 220 221 if (del_len == item_size) { 222 ret = btrfs_del_item(trans, root, path); 223 goto out; 224 } 225 ptr = (unsigned long)ref; 226 sub_item_len = name->len + sizeof(*ref); 227 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]); 228 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len, 229 item_size - (ptr + sub_item_len - item_start)); 230 btrfs_truncate_item(path, item_size - sub_item_len, 1); 231 out: 232 btrfs_free_path(path); 233 234 if (search_ext_refs) { 235 /* 236 * No refs were found, or we could not find the 237 * name in our ref array. Find and remove the extended 238 * inode ref then. 239 */ 240 return btrfs_del_inode_extref(trans, root, name, 241 inode_objectid, ref_objectid, index); 242 } 243 244 return ret; 245 } 246 247 /* 248 * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree. 249 * 250 * The caller must have checked against BTRFS_LINK_MAX already. 251 */ 252 static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans, 253 struct btrfs_root *root, 254 const struct fscrypt_str *name, 255 u64 inode_objectid, u64 ref_objectid, 256 u64 index) 257 { 258 struct btrfs_inode_extref *extref; 259 int ret; 260 int ins_len = name->len + sizeof(*extref); 261 unsigned long ptr; 262 struct btrfs_path *path; 263 struct btrfs_key key; 264 struct extent_buffer *leaf; 265 266 key.objectid = inode_objectid; 267 key.type = BTRFS_INODE_EXTREF_KEY; 268 key.offset = btrfs_extref_hash(ref_objectid, name->name, name->len); 269 270 path = btrfs_alloc_path(); 271 if (!path) 272 return -ENOMEM; 273 274 ret = btrfs_insert_empty_item(trans, root, path, &key, 275 ins_len); 276 if (ret == -EEXIST) { 277 if (btrfs_find_name_in_ext_backref(path->nodes[0], 278 path->slots[0], 279 ref_objectid, 280 name)) 281 goto out; 282 283 btrfs_extend_item(path, ins_len); 284 ret = 0; 285 } 286 if (ret < 0) 287 goto out; 288 289 leaf = path->nodes[0]; 290 ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char); 291 ptr += btrfs_item_size(leaf, path->slots[0]) - ins_len; 292 extref = (struct btrfs_inode_extref *)ptr; 293 294 btrfs_set_inode_extref_name_len(path->nodes[0], extref, name->len); 295 btrfs_set_inode_extref_index(path->nodes[0], extref, index); 296 btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid); 297 298 ptr = (unsigned long)&extref->name; 299 write_extent_buffer(path->nodes[0], name->name, ptr, name->len); 300 btrfs_mark_buffer_dirty(path->nodes[0]); 301 302 out: 303 btrfs_free_path(path); 304 return ret; 305 } 306 307 /* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */ 308 int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans, 309 struct btrfs_root *root, const struct fscrypt_str *name, 310 u64 inode_objectid, u64 ref_objectid, u64 index) 311 { 312 struct btrfs_fs_info *fs_info = root->fs_info; 313 struct btrfs_path *path; 314 struct btrfs_key key; 315 struct btrfs_inode_ref *ref; 316 unsigned long ptr; 317 int ret; 318 int ins_len = name->len + sizeof(*ref); 319 320 key.objectid = inode_objectid; 321 key.offset = ref_objectid; 322 key.type = BTRFS_INODE_REF_KEY; 323 324 path = btrfs_alloc_path(); 325 if (!path) 326 return -ENOMEM; 327 328 path->skip_release_on_error = 1; 329 ret = btrfs_insert_empty_item(trans, root, path, &key, 330 ins_len); 331 if (ret == -EEXIST) { 332 u32 old_size; 333 ref = btrfs_find_name_in_backref(path->nodes[0], path->slots[0], 334 name); 335 if (ref) 336 goto out; 337 338 old_size = btrfs_item_size(path->nodes[0], path->slots[0]); 339 btrfs_extend_item(path, ins_len); 340 ref = btrfs_item_ptr(path->nodes[0], path->slots[0], 341 struct btrfs_inode_ref); 342 ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size); 343 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len); 344 btrfs_set_inode_ref_index(path->nodes[0], ref, index); 345 ptr = (unsigned long)(ref + 1); 346 ret = 0; 347 } else if (ret < 0) { 348 if (ret == -EOVERFLOW) { 349 if (btrfs_find_name_in_backref(path->nodes[0], 350 path->slots[0], 351 name)) 352 ret = -EEXIST; 353 else 354 ret = -EMLINK; 355 } 356 goto out; 357 } else { 358 ref = btrfs_item_ptr(path->nodes[0], path->slots[0], 359 struct btrfs_inode_ref); 360 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name->len); 361 btrfs_set_inode_ref_index(path->nodes[0], ref, index); 362 ptr = (unsigned long)(ref + 1); 363 } 364 write_extent_buffer(path->nodes[0], name->name, ptr, name->len); 365 btrfs_mark_buffer_dirty(path->nodes[0]); 366 367 out: 368 btrfs_free_path(path); 369 370 if (ret == -EMLINK) { 371 struct btrfs_super_block *disk_super = fs_info->super_copy; 372 /* We ran out of space in the ref array. Need to 373 * add an extended ref. */ 374 if (btrfs_super_incompat_flags(disk_super) 375 & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF) 376 ret = btrfs_insert_inode_extref(trans, root, name, 377 inode_objectid, 378 ref_objectid, index); 379 } 380 381 return ret; 382 } 383 384 int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans, 385 struct btrfs_root *root, 386 struct btrfs_path *path, u64 objectid) 387 { 388 struct btrfs_key key; 389 int ret; 390 key.objectid = objectid; 391 key.type = BTRFS_INODE_ITEM_KEY; 392 key.offset = 0; 393 394 ret = btrfs_insert_empty_item(trans, root, path, &key, 395 sizeof(struct btrfs_inode_item)); 396 return ret; 397 } 398 399 int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root 400 *root, struct btrfs_path *path, 401 struct btrfs_key *location, int mod) 402 { 403 int ins_len = mod < 0 ? -1 : 0; 404 int cow = mod != 0; 405 int ret; 406 int slot; 407 struct extent_buffer *leaf; 408 struct btrfs_key found_key; 409 410 ret = btrfs_search_slot(trans, root, location, path, ins_len, cow); 411 if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY && 412 location->offset == (u64)-1 && path->slots[0] != 0) { 413 slot = path->slots[0] - 1; 414 leaf = path->nodes[0]; 415 btrfs_item_key_to_cpu(leaf, &found_key, slot); 416 if (found_key.objectid == location->objectid && 417 found_key.type == location->type) { 418 path->slots[0]--; 419 return 0; 420 } 421 } 422 return ret; 423 } 424 425 static inline void btrfs_trace_truncate(struct btrfs_inode *inode, 426 struct extent_buffer *leaf, 427 struct btrfs_file_extent_item *fi, 428 u64 offset, int extent_type, int slot) 429 { 430 if (!inode) 431 return; 432 if (extent_type == BTRFS_FILE_EXTENT_INLINE) 433 trace_btrfs_truncate_show_fi_inline(inode, leaf, fi, slot, 434 offset); 435 else 436 trace_btrfs_truncate_show_fi_regular(inode, leaf, fi, offset); 437 } 438 439 /* 440 * Remove inode items from a given root. 441 * 442 * @trans: A transaction handle. 443 * @root: The root from which to remove items. 444 * @inode: The inode whose items we want to remove. 445 * @control: The btrfs_truncate_control to control how and what we 446 * are truncating. 447 * 448 * Remove all keys associated with the inode from the given root that have a key 449 * with a type greater than or equals to @min_type. When @min_type has a value of 450 * BTRFS_EXTENT_DATA_KEY, only remove file extent items that have an offset value 451 * greater than or equals to @new_size. If a file extent item that starts before 452 * @new_size and ends after it is found, its length is adjusted. 453 * 454 * Returns: 0 on success, < 0 on error and NEED_TRUNCATE_BLOCK when @min_type is 455 * BTRFS_EXTENT_DATA_KEY and the caller must truncate the last block. 456 */ 457 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, 458 struct btrfs_root *root, 459 struct btrfs_truncate_control *control) 460 { 461 struct btrfs_fs_info *fs_info = root->fs_info; 462 struct btrfs_path *path; 463 struct extent_buffer *leaf; 464 struct btrfs_file_extent_item *fi; 465 struct btrfs_key key; 466 struct btrfs_key found_key; 467 u64 new_size = control->new_size; 468 u64 extent_num_bytes = 0; 469 u64 extent_offset = 0; 470 u64 item_end = 0; 471 u32 found_type = (u8)-1; 472 int del_item; 473 int pending_del_nr = 0; 474 int pending_del_slot = 0; 475 int extent_type = -1; 476 int ret; 477 u64 bytes_deleted = 0; 478 bool be_nice = false; 479 480 ASSERT(control->inode || !control->clear_extent_range); 481 ASSERT(new_size == 0 || control->min_type == BTRFS_EXTENT_DATA_KEY); 482 483 control->last_size = new_size; 484 control->sub_bytes = 0; 485 486 /* 487 * For shareable roots we want to back off from time to time, this turns 488 * out to be subvolume roots, reloc roots, and data reloc roots. 489 */ 490 if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) 491 be_nice = true; 492 493 path = btrfs_alloc_path(); 494 if (!path) 495 return -ENOMEM; 496 path->reada = READA_BACK; 497 498 key.objectid = control->ino; 499 key.offset = (u64)-1; 500 key.type = (u8)-1; 501 502 search_again: 503 /* 504 * With a 16K leaf size and 128MiB extents, you can actually queue up a 505 * huge file in a single leaf. Most of the time that bytes_deleted is 506 * > 0, it will be huge by the time we get here 507 */ 508 if (be_nice && bytes_deleted > SZ_32M && 509 btrfs_should_end_transaction(trans)) { 510 ret = -EAGAIN; 511 goto out; 512 } 513 514 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 515 if (ret < 0) 516 goto out; 517 518 if (ret > 0) { 519 ret = 0; 520 /* There are no items in the tree for us to truncate, we're done */ 521 if (path->slots[0] == 0) 522 goto out; 523 path->slots[0]--; 524 } 525 526 while (1) { 527 u64 clear_start = 0, clear_len = 0, extent_start = 0; 528 bool should_throttle = false; 529 530 fi = NULL; 531 leaf = path->nodes[0]; 532 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); 533 found_type = found_key.type; 534 535 if (found_key.objectid != control->ino) 536 break; 537 538 if (found_type < control->min_type) 539 break; 540 541 item_end = found_key.offset; 542 if (found_type == BTRFS_EXTENT_DATA_KEY) { 543 fi = btrfs_item_ptr(leaf, path->slots[0], 544 struct btrfs_file_extent_item); 545 extent_type = btrfs_file_extent_type(leaf, fi); 546 if (extent_type != BTRFS_FILE_EXTENT_INLINE) 547 item_end += 548 btrfs_file_extent_num_bytes(leaf, fi); 549 else if (extent_type == BTRFS_FILE_EXTENT_INLINE) 550 item_end += btrfs_file_extent_ram_bytes(leaf, fi); 551 552 btrfs_trace_truncate(control->inode, leaf, fi, 553 found_key.offset, extent_type, 554 path->slots[0]); 555 item_end--; 556 } 557 if (found_type > control->min_type) { 558 del_item = 1; 559 } else { 560 if (item_end < new_size) 561 break; 562 if (found_key.offset >= new_size) 563 del_item = 1; 564 else 565 del_item = 0; 566 } 567 568 /* FIXME, shrink the extent if the ref count is only 1 */ 569 if (found_type != BTRFS_EXTENT_DATA_KEY) 570 goto delete; 571 572 control->extents_found++; 573 574 if (extent_type != BTRFS_FILE_EXTENT_INLINE) { 575 u64 num_dec; 576 577 clear_start = found_key.offset; 578 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); 579 if (!del_item) { 580 u64 orig_num_bytes = 581 btrfs_file_extent_num_bytes(leaf, fi); 582 extent_num_bytes = ALIGN(new_size - 583 found_key.offset, 584 fs_info->sectorsize); 585 clear_start = ALIGN(new_size, fs_info->sectorsize); 586 587 btrfs_set_file_extent_num_bytes(leaf, fi, 588 extent_num_bytes); 589 num_dec = (orig_num_bytes - extent_num_bytes); 590 if (extent_start != 0) 591 control->sub_bytes += num_dec; 592 btrfs_mark_buffer_dirty(leaf); 593 } else { 594 extent_num_bytes = 595 btrfs_file_extent_disk_num_bytes(leaf, fi); 596 extent_offset = found_key.offset - 597 btrfs_file_extent_offset(leaf, fi); 598 599 /* FIXME blocksize != 4096 */ 600 num_dec = btrfs_file_extent_num_bytes(leaf, fi); 601 if (extent_start != 0) 602 control->sub_bytes += num_dec; 603 } 604 clear_len = num_dec; 605 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { 606 /* 607 * We can't truncate inline items that have had 608 * special encodings 609 */ 610 if (!del_item && 611 btrfs_file_extent_encryption(leaf, fi) == 0 && 612 btrfs_file_extent_other_encoding(leaf, fi) == 0 && 613 btrfs_file_extent_compression(leaf, fi) == 0) { 614 u32 size = (u32)(new_size - found_key.offset); 615 616 btrfs_set_file_extent_ram_bytes(leaf, fi, size); 617 size = btrfs_file_extent_calc_inline_size(size); 618 btrfs_truncate_item(path, size, 1); 619 } else if (!del_item) { 620 /* 621 * We have to bail so the last_size is set to 622 * just before this extent. 623 */ 624 ret = BTRFS_NEED_TRUNCATE_BLOCK; 625 break; 626 } else { 627 /* 628 * Inline extents are special, we just treat 629 * them as a full sector worth in the file 630 * extent tree just for simplicity sake. 631 */ 632 clear_len = fs_info->sectorsize; 633 } 634 635 control->sub_bytes += item_end + 1 - new_size; 636 } 637 delete: 638 /* 639 * We only want to clear the file extent range if we're 640 * modifying the actual inode's mapping, which is just the 641 * normal truncate path. 642 */ 643 if (control->clear_extent_range) { 644 ret = btrfs_inode_clear_file_extent_range(control->inode, 645 clear_start, clear_len); 646 if (ret) { 647 btrfs_abort_transaction(trans, ret); 648 break; 649 } 650 } 651 652 if (del_item) { 653 ASSERT(!pending_del_nr || 654 ((path->slots[0] + 1) == pending_del_slot)); 655 656 control->last_size = found_key.offset; 657 if (!pending_del_nr) { 658 /* No pending yet, add ourselves */ 659 pending_del_slot = path->slots[0]; 660 pending_del_nr = 1; 661 } else if (pending_del_nr && 662 path->slots[0] + 1 == pending_del_slot) { 663 /* Hop on the pending chunk */ 664 pending_del_nr++; 665 pending_del_slot = path->slots[0]; 666 } 667 } else { 668 control->last_size = new_size; 669 break; 670 } 671 672 if (del_item && extent_start != 0 && !control->skip_ref_updates) { 673 struct btrfs_ref ref = { 0 }; 674 675 bytes_deleted += extent_num_bytes; 676 677 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, 678 extent_start, extent_num_bytes, 0); 679 btrfs_init_data_ref(&ref, btrfs_header_owner(leaf), 680 control->ino, extent_offset, 681 root->root_key.objectid, false); 682 ret = btrfs_free_extent(trans, &ref); 683 if (ret) { 684 btrfs_abort_transaction(trans, ret); 685 break; 686 } 687 if (be_nice) { 688 if (btrfs_should_throttle_delayed_refs(trans)) 689 should_throttle = true; 690 } 691 } 692 693 if (found_type == BTRFS_INODE_ITEM_KEY) 694 break; 695 696 if (path->slots[0] == 0 || 697 path->slots[0] != pending_del_slot || 698 should_throttle) { 699 if (pending_del_nr) { 700 ret = btrfs_del_items(trans, root, path, 701 pending_del_slot, 702 pending_del_nr); 703 if (ret) { 704 btrfs_abort_transaction(trans, ret); 705 break; 706 } 707 pending_del_nr = 0; 708 } 709 btrfs_release_path(path); 710 711 /* 712 * We can generate a lot of delayed refs, so we need to 713 * throttle every once and a while and make sure we're 714 * adding enough space to keep up with the work we are 715 * generating. Since we hold a transaction here we 716 * can't flush, and we don't want to FLUSH_LIMIT because 717 * we could have generated too many delayed refs to 718 * actually allocate, so just bail if we're short and 719 * let the normal reservation dance happen higher up. 720 */ 721 if (should_throttle) { 722 ret = btrfs_delayed_refs_rsv_refill(fs_info, 723 BTRFS_RESERVE_NO_FLUSH); 724 if (ret) { 725 ret = -EAGAIN; 726 break; 727 } 728 } 729 goto search_again; 730 } else { 731 path->slots[0]--; 732 } 733 } 734 out: 735 if (ret >= 0 && pending_del_nr) { 736 int err; 737 738 err = btrfs_del_items(trans, root, path, pending_del_slot, 739 pending_del_nr); 740 if (err) { 741 btrfs_abort_transaction(trans, err); 742 ret = err; 743 } 744 } 745 746 ASSERT(control->last_size >= new_size); 747 if (!ret && control->last_size > new_size) 748 control->last_size = new_size; 749 750 btrfs_free_path(path); 751 return ret; 752 } 753